The present invention disclosed herein relates to a display device and a method of manufacturing the same, and more particularly, to a display device including a self-light emitting pixel layer and a reflective pixel layer and a method of manufacturing the same.
In existing display technologies, displays may be classified into transmissive displays, self-light emitting displays, and reflective displays. Representative examples of the transmissive displays may include thin film transistor liquid displays (TFTLCDs). Since such a TFTLCD has superior image quality, TFTLCD may be widely used for televisions (TVs), monitors and cell phones and lead display markets. However, the TFTLCD has drawbacks in that it has high power consumption and consumes high capacity of electricity and is not flexible.
Representative examples of the self-light emitting displays may include organic light-emitting diodes (OLEDs) and plasma display panels (PDPs). Since such a self-light emitting display emits light from its pixel itself, the self-light emitting display may have a fast response speed, a high contrast ratio, and superior color reproduction when compared to that of an LCD. Also, since such an OLED is capable of being manufactured with an ultra-thin thickness, the OLED is being applied into flexible displays and transparent displays.
The reflective displays may include electrophoretic displays, electro wetting displays, and microelectromechanical systems. Such a reflective display may be driven by reflecting external light such as sunlight or electric light. Thus, the reflective display may realize a clearer image when its surrounding is brighter. Also, since the reflective display is driven by the external light, the reflective display may have low power consumption. However, the reflective display may have relatively poor image quality when compared to those of the transmissive display and the self-light emitting display.
Each of the transmissive display and the self-light emitting display may have a clearer image at the indoor places or dark places. However, each of the transmissive display and the self-light emitting display may be deteriorated in visibility at the outdoor places or bright places. Thus, studies with respect to displays that provide clear images at the indoor or outdoor places and have low power consumption are being conducted.
For example, there is a structure in which a switching layer that is switchable between a transparent state and an opaque state is disposed between a transparent OLED and a background reflector. However, since the switching layer does not operate for each pixel, but equally operate on the overall pixels, the display may not be realized as a complete reflective display, but serve as only a supporter for supplementing an OLED screen by using a reflection function. That is, the display may not realize a moving picture having various colors, but realize an image having a simple color and shape such as a color of a wallpaper or a corporate logo. Also, there is a transflective display in which an LCD that is the transmissive display is combined with a reflective device as a representative dual mode display to which the reflective display is coupled. Generally, the dual mode LCD display may have a structure in which the reflective device such as a mirror is added to a structure that is equal to that of the normal LCD. When a backlight is turned off, external light is reflected by a mirror through a liquid crystal to serve as the reflective display. On the other hand, when the backlight is turned on, the dual mode LCD display operates with the same function as the general LCD to serve as the transmissive display. However, it is difficult to realize the flexible display because it is based on the liquid crystal.
In a case where the self-light emitting pixels are manufactured, and then the reflective pixels are successively formed on the self-light emitting pixels when the dual mode display including the self-light emitting and reflective pixels is manufactured, the self-light emitting pixels may be degraded during the reflective pixel manufacturing process. Thus, it is advantageous to utilize a process of bonding the pixels to each other. The most important thing is to maintain flatness of the bonding surface when the self-light emitting and the reflective pixels are bonded to each other. On the other hand, in a case of a carbon-based transparent electrode and an inorganic-based transparent electrode, which are highly likely to be used as upper electrodes of the display, the each of the carbon-based transparent electrode and the inorganic-based transparent electrode may have high surface resistance. Thus, to introduce the carbon-based transparent electrode and the inorganic-based transparent electrode into large-scale panels, a technology for reducing the surface resistance such as low-resistance auxiliary wires has to be introduced. However, if such a low-resistance auxiliary wire is introduced, a height difference may occur by a height of the auxiliary wire. Thus, due to the height difference, there is a limitation in bonding of the self-light emitting pixel and the reflective pixel.